Hu Xiaojun, Xing Xiaorong, Zhang Fan, Li Bingzhi, Chen Senlin, Wang Bo, Qin Jiaolong, Miao Jie
School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China.
School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
Toxics. 2025 Jan 5;13(1):36. doi: 10.3390/toxics13010036.
Recently, the activation of chlorine dioxide (ClO) by metal(oxide) for soil remediation has gained notable attention. However, the related activation mechanisms are still not clear. Herein, the variation of iron species and ClO, the generated reactive oxygen species, and the toxicity of the degradation intermediates were explored and evaluated with nanoscale zero-valent iron (nFe) being employed to activate ClO for soil polycyclic aromatic hydrocarbon (PAH) removal. With an optimized ClO/nFe molar ratio of 15:1 and a soil/water ratio of 3:1, the degradation efficiency of phenanthrene improved 12% in comparison with that of a ClO-alone system. The presence of nFe significantly promoted ClO consumption (improved 85.4%) but restrained ClO generation (reduced 22.5%). The surface Fe(II) and soluble Fe(II) in the ClO/nFe system was 2.0-fold and 2.8-fold that in the nFe system after 2 min. Electron paramagnetic resonance analysis, along with quenching experiments, revealed that Fe(IV), HOCl, and •OH dominated phenanthrene degradation in a ClO/nFe system, with oxidation contributions, respectively, of 34.3%, 52.8% and 12.9%. The degradation intermediates of PAHs in the ClO/nFe system had lower estimated toxicity than those of the ClO system. The lettuces grown in ClO/nFe-treated soil displayed better results in bioassay indexes than those grown in ClO-treated soil. This study offers new perspectives for the remediation of organic-pollutant-contaminated soil by using metal-activated ClO technology.
最近，金属（氧化物）对二氧化氯（ClO）的活化用于土壤修复已受到显著关注。然而，相关的活化机制仍不清楚。在此，研究并评估了铁物种和ClO的变化、产生的活性氧物种以及降解中间体的毒性，采用纳米零价铁（nFe）活化ClO以去除土壤中的多环芳烃（PAH）。在优化的ClO/nFe摩尔比为15:1和土壤/水比为3:1的条件下，与单独使用ClO的体系相比，菲的降解效率提高了12%。nFe的存在显著促进了ClO的消耗（提高了85.4%），但抑制了ClO的生成（降低了22.5%）。2分钟后，ClO/nFe体系中的表面Fe(II)和可溶性Fe(II)分别是nFe体系中的2.0倍和2.8倍。电子顺磁共振分析以及猝灭实验表明，在ClO/nFe体系中，Fe(IV)、HOCl和•OH主导了菲的降解，氧化贡献分别为34.3%、52.8%和12.9%。ClO/nFe体系中PAHs的降解中间体的估计毒性低于ClO体系中的中间体。在ClO/nFe处理过的土壤中生长的生菜在生物测定指标上比在ClO处理过的土壤中生长的生菜表现更好。本研究为利用金属活化ClO技术修复有机污染物污染土壤提供了新的视角。
